.page{
    padding: 20px;
    display: inline-block; 
    width: 100%;
   height: 100vh;
   position: relative;
   overflow: hidden;
    .title{
        font-size: 22px;
        line-height: 80px;
    }
    .content-item{
        font-size: 16px;
        line-height: 25px;
        margin-bottom: 30px;
    }
    .page-num{
        position: absolute;
        bottom: 15px;
        right: 15px;
        font-size: 12px;
        color: gray;
    }
    .catalog-back{
        text-align: center;
        display: block;
        color: #333333;
    }
   
}
.night{
    background-color: #000101;
    color:#5f5f5f;

}
.diurnal{
    background-color: #faf9f7;
    color: #333333;
}
.head-up{
    position: fixed;
    top: -30px;
    left: 0;
    width: 100%;
    height: 30px;
    color: #eee;
    display: flex;
    align-items: center;
    background-color: rgba(0,0,0,0.5);
    z-index: 99;
    transition: all 0.3s;
}
.head-down{
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 30px;
    color: #eee;
    display: flex;
    align-items: center;
    background-color: rgba(0,0,0,0.5);
    z-index: 99;
    transition: all 0.3s;
}
.off-text{
    position: absolute;
    right: 10px;
}
